Synchronized clock



April 1934- R. c. ALLEN 1,954,780

I swcaaomzsn CLOCK Filed April 26, 1930 2 Sheets-Sheet 1 \H'nllul'! 2 Minimum anvwtoz Q 3| XMMM Q flu 2 $3 k, emu:

' April 17, 1934. R, ALLEN 1,954,780

SYNCHRONI ZED CLOCK Filed April 26, 1930 2 Sheets-Sheet 2 Elwuentoz Patented Apr. 17, 1934 SYNCHRONIZED CLOCK Ralph Charles Allen,

Endicott, N. Y., asslgnor,

by mesne assignments, to International Businass Machines Corporation,

New "York, N. Y., a

corporation of New York Application April 26,- 1930, Serial No. 447,482 9 Claims. (Cl. 5824) This invention relates to improvements in synchronized clock systems and in secondary clocks therefor.

More particularly the invention relates to an improved impulse accepting selecting and rejecting means which will provide greater simplicity and reliability in synchronized clock systems of the so-called one-wire or single circuit type.

In certain respects the present application constitutes an improvement and simplification of the one-wire systems shown and described in Bryce and Getz Patent No. 1,740,330 and in Bryce application Serial No. 62,745, filed October 16, 1925, now Patent No. 1,875,801 of September 6, 1932.

" In the former, resistance means was used in the secondary clocks to accept or reject impulses and variation of action over the one-wire system was obtained by varying voltage by the master clock..

In the latter, variation ofcontrol of remote secondaries was obtained by varying the direction of impulse flow by the master clock and utilizing switching devices and polarized magnets at the secondary clocks.

According to the present invention control from the master clock is secured by varying the direction of impulse flow over the single circuit and control of the secondaries or of a distant and remote synchronized clock system or systems is provided by means of a polarity trap, electric valve or like device which is preferably of the dry plate rectifier type. Accordingly, polarized magnets are rendered unnecessary andthe switching devices may be materially simplified.

Another object of the present invention resides in the provision of improved means for selecting and rejecting impulses in a clock system in accordance with the direction of flow of the impulses which are received to the general end that simplicity of construction may be secured and also to the general end that greater reliability of ac-' tion may be secured.

A further object of the present invention resides in the provision of a system and arrangement of secondary clock or remote control unit for a distant secondary clock system which will provide increased reliability of operation in that reliance need not be placed upon a single impulse of reversed direction for re-initiating action. In contradistinction a multiplicity of re-initiating impulses are available for re-initiating action when required.

Another object of the present invention resides in the provision of a synchronized clock system embodying secondaries of such type that existing three-wire controlled secondary clocks may be readily altered by a simple addition and without change of the impulse magnet from a simple magnet to a polarized magnet, to permit the same to properly function in conjunction with a onewire system from a master clock.

A further object of the present invention resides in the'provision of a one-wire synchronized clock system embodying secondary clocks which will provide for the reliability and sureness of operation heretofore only attainable with threewire synchronized impulse clock systems.

A further object of the present invention resides in the provision of a clock system in which the devices used for current rectification of the supply to the system are also utilized elsewhere in the system for controlling purposes.

A further object of the present invention resides in the provision of asymmetrical conductor means and devices in novel relations in a clock system in order that improved and-novel results may be secured.

Further and other objects 01' the present invention will be hereinafter panying specification and claims and shown in the drawings, which by way of illustration show what I now consider to be a preferred embodiment of the invention.

In the drawings:

Figures 1 and 1a taken together show a circuit diagram of the complete system;

Fig. 2 is a detail view of a modification of the circuit switching devices and circuits in the secondary clock; and

Fig. 3 is a detail view of one of the secondaries.

The master clock in its general details may be of any desired form. For example, it can be that shown and described in United States Patents Nos. 1,687,491 and 1,740,330. .It is suflicient to here state that the master clock includes the usual minute contacts designated 17, which are closed once a minute on the minute. There are also included, contacts 19 which are the contacts for sending out the rapid or stepping up impulses. There are also provided contacts 14 and while these contacts may be set to close and open at set forth in the accomany desired time, according to the present em- Contacts 16 are also provided which are adapted to closeafter the 59th minute, say for example, 10 seconds after and remain closed and reopen 30 seconds later at 59 minutes, 40 seconds.

The secondary clocks which are employed are also of the usual impulse type and the details of the driving mechanism of such impulse clocks need not be here described in detail since they are the same as set forth in the aforementioned patents and shown in detail in Bryce Patent No. 1,752,939 (see also Fig. 3). His sufiicient to here state that they are provided with impulse magnets designated 21 and with the cam actuated contacts 25-26 controlled by synchronizing cam As shown in the drawings there are three secondary clocks designated X, Y and Z. The X clock is shown on time, the Y clock 15 minutes fast and the Z clock 15 minutes slow.

It will be understood that the relation of the cam devices to the contact elements 25-26 of each secondary clock is such that contacts 25 open at the 59th minute and concurrently contacts 26 close. Contacts 25 reclose at any time after the 60th minute but before the 44th minute and contacts 26 correspondingly re-open any time after 60 or before 44.

The contact parts in the secondary clocks are also so arranged that at no time except momentarily during the shifting of the center blade are both sets of contacts open.

Referring to the circuit diagram current is supplied to the system from a pair of A-C mains designated 100, to a transformer generally designated 102. It will be understood that this transformer is preferably located adjacent the master clock. From the transformer there are tapped off three circuits, one circuit 10% leads from the transformer serially through contacts '16 and 19. In shunt with the circuit 104 just traced, is another circuit 106 which leads through contacts 17-. Branching off from the circuit 106 is a circuit 108 which leads through contacts 14, through the reversing switch relay coil 4 andthence back to the transformer 102. There is also a return circuit 110 which leads from the juncture of circuits 106 and 104 back through a master relay coil 36 and thence back to the transformer. Adjacent the master clock there is also a rectiher 112. Preferably this rectifier is of the well known dry plate copper oxide type employing copper plates, certain plates having a coating of copper oxide thereon.. Such rectifiers are well known and are foundon the market. This recti- -'fier is supplied with alternating currentthrough the circuit 114 and current flow is established through .it by the energization of coil 36, which when energized-closes relay points 38 and supplies alternating current from the transformer to the rectifier 112. 116 and 118 represent the output mains from rectifier, 116 transmitting current of negative polarity and 118 transmitting current of positive polarity to the switch points of the reversing switch generally designated 120. tThe rectifier is preferably connected up to supply full wave rectification.

The blades of the reversing switch are connected as shown, one blade leading to ground designated G and the other to the line A which extends to the various secondary clocks or to a remotely disposed secondary clock system or systems as will be later described.

The various circuits and contacts of the master clock are adapted to impart a series of unidirectional minute impulses over the line A be- Accordingly, these may be termed incoming impulses on line A. The outgoing impulses going out through the ground and the return being via wire or line A. Incoming impulses continue to flow minute by minute over line A until the time that the two second contacts 19 come into action when a series of more rapid incoming impulses will be 'online A. Two second contacts 19 come.

into action upon the closure of contacts 16 at the time previously indicated.

It will also be understood that the circuit relation of the contacts in the master clock and the time of action of the contacts is such that the reversing switch 44 will again be picked up to the position shown before the 60th minute and upon the 60th minute an outgoing impulse will again flow out over the line A, thus at the 60th minute there will be a reversal of direction of impulses on line A.v

To control and bring about synchronizing in each secondary clock, each clock is provided with an impulse accepting and rejecting device. This may be also considered as a polarity trap, a valve device, or asymmetrical conductor, and functions to permit impulses to flow through it in one direction and to prevent or substantially suppress the flow ofimpulses therethrough in the opposite direction. Such device is indicated on circuit diagram at 122 and preferably comprises a copper oxide rectifier unit utilizing the usual copper oxide rectifier of the dry plate type. The relation of the plates in each of these rectifier units is such that impulses are permitted to flow through them in the direction indicated by the arrows, but are not permitted to fiow through in reverse direction.

A number of various synchronizing conditions will now be described for the different clocks X...

Y and Z. I

Referring to clock X. it will be noted that contacts 25 are closed and 26 are open. With this relation of the contact elements, all impulses whether incoming or outgoing will flow to the impulse magnet 21 and the magnet will continue to advance the clock until contacts 25 open and 26 close. This will occur at the 59th minute position of the secondary clock on this on time secondary clock X. Thereafter the rapid stepping up impulses willnot effect the impulse magnet since these rapid stepping up impulses are of incoming character and cannot accordingly flow through contacts 26 and through the trap 122 in reverse direction. Upon the 60th minute, however, the direction of the impulse flow through the trap 122 is reversed and the magnet 21 again receives current and steps ed the clock in on time relation. As in previous systems these contacts shift their relations to the position shown for the X clock before the 44th minute position of the master clock so that contacts 25 are reestablished before that time.

If a secondary clock is fast for example clock Y, contacts 26 will be closed. Under these conditions the inflowing impulses on line A after the 44th minute cannot energize magnet 21 and the iii clock will remain out of action until outgoing impulses again flow over A through the trap 122 in the direction shown by the arrow at which time there is resumption of operation of this will then be effective to rapidly energize the magnet 21 and step up the clock. When the clock reaches an on time condition contacts 25 will open and 26 re-close putting the clock in position to again step 01f at the th minute as before.

Referring to the drawings Fig. 2, there is here shown a somewhat modified arrangement of circuit and switching device for the secondary clocks. The impulse magnet 21 is provided asbefore as well as the trapping device or valve 122. In lieu of using a double pair of contacts, a single pair of contacts 25 is provided which are connected in shunt around the trap 122. This modiiied circuit and switching arrangement functions in the same manner as before and need not be r further described, except o say that when contacts 25 are closed all impulses will be effective to operate magnet 21 irrespective of their direction of flow and that when contacts 25 are open the only impulses which will be efiective will be impulses which flow in through the trap. and out through the impulses magnet to ground. Impulses flowing in reverse direction will be ineifective on the impulse magnet.

The polarity trap device and dry plate rectifier unit also may be used in operating a three-wire synchronized clock system at a distance. In this respect the present application constitutes an improvement of copending Bryce application Serial No. 377,971, filed July 13, 1929, now Patent No. 1,908,112 of May 9, 1933, wherein polarized magnet devices were utilized for controlling a three-wire system of secondary clocks at a remote point over a single line circuit from a master clock. In lieu of using polarized magnet devices at the distant point as in that application, use is made of rectifier elements or an asymmetrical conductor in a new relation as will now be described. F

The reference character D, generally designates a remote synchronized clock system provided with three wires B, A and C which connect to the usual secondary clocks. The secondary clocks of this remote system may be those shown and described in Bryce Patent No. 1,687,-

491, wires B, A and C corresponding to the A, B and C circuits of this patent.

At theremote point there is provided an alter nating current source 100A, a transformer 102A and a dry plate rectifier 112A. There is also provided a supplementary polarity trap device 124' which is disposed to permit current flow therethrough in the direction shown by the arrow. shunted around the polarity trap 124 is a circuit 126, the mid point of which is connected to ground G and disposed in circuit 126 are two relay magnet coils 128 and 130. Relay magnet coil 128 when energized closes contacts 132 and relay magnet coil '130 when energized is adapted to close contacts 134. From the positive terminal of the rectifier 112A a circuit 136 leads to the terminal or lines C of the remote three-wire secondary clock system. From the negative terminal of the rectifier 112A a circuit 138 leads to the A wire or terminal of the clock system. Circuit 138 also has a branch circuit leading to the upper contact points 134 and the other relay contact point is connected to terminal or wire B.

In operation, coil 128 is energized for each impulse flowing over wire A irrespective of the direction of flow. Accordingly, the rectifier 112A will receive current whenever an impulse flows over A and suchJmpulses will always flow out over line A each time that there is an impulse on line A. During the period, however, when impulses flow over wire A in reverse or what were previously termed incoming directions, such impulses cannot flow through the trap 124 in reverse direction and accordingly during this period, 139 will be de-energized. This will suppress the sending out of impulses out over wire B and provide the desired conditions for actuating a threewire synchronizing clock system at the remote point. The suppression of the sending out of impulses upon the B wire corresponds to the period when the B wire is dead in the Bryce Patent No, 1,687,491 previously referred to.

It will accordingly be appreciated that according to the present invention, several uses are provided for the rectifier elements. First they are used for rectifying an alternating current supply for the system, second they are used as polarity traps, asymmetrical conductors or valves to accept or reject transmitted current impulses at the controlled devices whether there be secondary clocks or switching devices for controlling another clock system.

What I claim is:

1. A clock system including amaster'clock and secondary clocks, a source of alternating current supply for the system, means for rectifying the alternating current and for transmitting rectified current of different polarities at different times to the secondaries, and rectifier-like devices in the secondaries for controlling their operation and synchronizing the same under the control of the master clock.

2. A clock system including in combination a master clock and single line circuit over which all impulses are transmitted to remote points which impulses are unidirectional but which have different polarity at different times as determined by the master clock, and at a point or points remote from the master clock of impulse accepting, rejecting and selecting devices which include polarity trap means.

-3. In a clock system wherein a single circuit transmits unidirectional impulses and in which the polarity of the unidirectional impulses varies at different times and including in combination, of an impulse accepting, selecting and rejecting means which permits certain impulses to flow from the single circuit to chronological control devices, and which hinders the flow of other impulses having a reverse polarity with respect to the other impulses, said means comprising polarity trap in the impulse circuit.

4. An impulse clock system adapted for operation wholly upon alternating current supply with secondary clocks arranged for impulse advance and synchronization wholly by unidirectional current supplied thereto from a. master clock whereby simplification and improved operation of the secondary clocks is secured, said system comprising a master clock, buses at the master clock to receive alternating current impulses, a single line circuit extending from the master to the secondary clocks, rectifying means at'the master clock for rectifying received alternating current to provide for unidirectional current supply to be sent out over the single line circuit to directional impulses of one polarity for one timeperiod and to thereafter send out unidirectional impulses of another polarity for another time period and for again repeating the sending of unidirectional impulses of the first mentioned polarity, each secondary clock comprising an impulse magnetwhich is effectively operable by unidirectional impulses of either polarity when such impulses are received by the impulse magnet, and impulse accepting, rejecting and selecting means at each secondary clock, said ;means being controlled by the chronological condition of the secondary clock and including a switching means and acooperating polarity trap which cooperates to accept unidirectional impulses of one polarity, to reject unidirectional impulses of the polarity and to accept unidirectional impulses of reverse polarity whereby impulse advance and synchronization of the secondary clock may be effected.

5. A clock system comprising in combination with a master clock one or more secondary clocks and a single line circuit therebetween, means in' the masterv clock for sending to the said clocks over the single line circuit unidirectional im pulses of one polarity for one period as determined by the chronological condition of the master clock and unidirectional impulses of a reverse polarity for another period as determined by the chronological condition of the master clock, each secondary clock including an impulse magnet and each secondary clock being operable for impulse advance and synchronization wholly by unidirectional impulses of one polarity or the other and synchronization control means in each secondary clock controlled by the chronological condition of .the secondary clock and comprising a polarity trap to suppress or permit efiective'flow or impulses to the impulse magnet according to the polarity of.the received unidirectional impulses and according to the chronologicalcondition of the secondary clock.

6. A clock system comprising in combination a master clock and one or more secondary clocks,

a single line circuit therebetween, means in the master clock for sending out unidirectional im-,

pulses of one polarity at certain times as determined by the chronological condition of the master clock and for sending out ever said single line circuit at other times as determined by the chronological condition 01' the master clock unidirectional impulses of a'reverse polarity and impulse magnets in each secondary clock operable by impulses of either polarity, and impulse selecting,

accepting and rejecting means in each secondary clock for accepting and rejecting impulses for flow to the impulse magnet, said means comprising a polarity trap, and said means being controlled by the chronological condition of the secondary clock.

. 7. A clock system for use in connection with commercial alternating current supply and comprising in combination, master clock controlled means including static rectifying means for converting the supplied alternatingcurrent into unidirectional currents of time controlled polarity and duration and supplying only such unidirectional currents to secondary clocks, and a plurality of secondary clocks controlled wholly by the said unidirectional currents whereby direct' current magnets may be used in said secondary clocks and the use of alternating current magnets therein rendered unnecessary, each of said secondary clocks including-an electromagnet energized only by unidirectional current and an asymmetrical conductor for controlling effective energization of said magnet according to the polarity of the received unidirectional currentj 8. A clock system comprising in combination, a plurality of secondary clocks, means for transmitting at difi'erent times unidirectional currents of difierent polarities to said secondary clocks, and means in each secondaryclock for controlling the operation and synchronization oi that secondary clock according tothe polarity of the received current, said last mentioned means including an asymmetricalccnductor which offers greater impedance to flow of current in one direction than it does to flow of current in the opposite direction.

9. A secondary clock comprising in combination, time-indicating mechanism, means com-' ing device and connected to said translating de.--

vice whereby said second named means controls the energization of said translating device, in accordance with the chronological condition of the clock.

RALPH CHARLES ALLEDL 

